The present invention relates generally to a cassette container case for storing a magnetic tape cassette, and more particularly to an improved cassette container case for storing a magnetic tape cassette for audio use or the like.
When storing an audio type magnetic tape cassette, the cassette is generally placed in a magnetic tape cassette container case made of a plastic material. The magnetic tape cassette has a front open portion into which a magnetic head, etc., is inserted when loading the cassette into a recording/reproducing device, the magnetic tape running across the front open portion during recording and reproduction. However, without sole way of enclosing the cassette, dust is liable to enter the cassette through the front open portion, and there is a risk that the user's fingers, etc., may contact the magnetic tape. In order to prevent such difficulties and to protect the entire cassette, a cassette container case is commonly used.
FIG. 1 shows the basic construction of a conventional cassette container case. The cassette container case 31 has a lid 32 having a pocket portion 34 for receiving a cassette 20, and a casing 35 having a pair of rotation-preventing projections 7 which are adapted to be inserted into respective shaft insertion holes 22 of the cassette 20.
In the cassette container case 31, pivot pins formed on right and left side walls of the casing 35 are fitted in corresponding through-holes formed in the right and left side walls of the pocket portion 34. With this arrangement, the lid 32 and the casing 35 can be opened and closed much like a door. The thickness of the cassette container case 31 between its walls 33 and 36 opposed respectively to the front and rear faces of the cassette 20 corresponds to the thick portion 21 of a cassette 20 in the region of its front opening. Therefore, except for the thick portion 21, the thickness l.sub.1 of the cassette container case 31 is considerably greater than the thickness l.sub.2 of the cassette 20.
Thus, when the cassette 20 is placed in the cassette container case 31 for storage purposes, a considerably greater storage space is required than if the cassette 20 were stored without a case. For this reason, if the user wishes to store as many cassettes 20 as possible in a limited space, for example, in an automobile, the user often refrains from using cassette container cases 31. However, if the cassette 20 is stored without the use of a cassette container case 31, dust tends to enter the cassette as described above, which results in a problem in that the recording and reproducing characteristics of the magnetic tape are degraded.
In order to overcome the above problems, the Applicant of the present invention has earlier proposed thin-type cassette container cases. (See U.S. Pat. Nos. 4,648,507 and 4,627,534).
In such a thin-type cassette container case, recesses for receiving the thick portion of the cassette at the front portion of the cassette are formed in an openable distal portion of the cassette container case.
The improved cassette container case disclosed in U.S. Pat. No. 4,627,534 will now be described with reference to FIG. 2. The cassette container case 11 shown in FIG. 2 has a lid 12 having a pocket portion 14, and a casing 15 which is pivotally connected to the lid 12 as in the conventional cassette container case. A recess 18 for receiving the thick portion 21 of a cassette 20 is formed in a wall 13 of the lid 12 opposed to the face of the cassette. Another recess 18 for receiving the thick portion 21 of the cassette is also formed in a wall 16 of the casing 15 opposed to the face of the cassette. A pair of rotation-preventing projections 7, similar to those of the conventional cassette case, and which are insertable into reel shaft insertion holes 22, are also formed on the wall 16.
The two recesses 18 are provided in the inner surfaces of the case in opposed relation to each other. Each recess 18 is shaped to receive the thick portion 21, that is, each recess has a shape (for example, a trapezoidal shape) flaring outward away from the axis of rotation (opening and closing movement) of the lid 12 and the casing 15.
Although not shown in the drawings, protrusions are formed on right and left side walls 19 of the casing 15, and respective depressions are formed in right and left side walls of the pocket portion 14 opposed to the walls 19. The protrusions are engageable in the depressions when the lid of the cassette container case 11 is closed, thereby preventing the lid from being accidentally opened during the storage of the cassette.
When the lid of the cassette container case 11 is in the closed position, the spacing between the wall 13 and the wall 16 is only slightly greater than the thickness l.sub.2 of the cassette 20 in areas other than the thick portion 21, and the spacing between the two recesses 18 is only slightly greater than the thickness l.sub.5 of the thick portion 21.
Therefore, the improved cassette container case 11 shown in FIG. 2 has a much smaller thickness than the earlier cassette container case, the space required for storing it is much reduced, and the improved case is very handy for carrying.
An index card 41 as shown in FIG. 3 is attached to the cassette container case 31 shown in FIG. 1, and desired data can be written on the index card 41. More specifically, the index card is positioned in such a manner that a folded portion 42 of a channel-shaped cross-section is fitted in the pocket portion 34, with a flat portion 43 laid over the flat wall 33 of the lid 32.
However, when the index card 41 is applied to the improved cassette container case 11 shown in FIG. 2, a problem is encountered. That is, since the recesses 18 are provided at the open side of the thin-type cassette container case 11, when the index card 41 is provided on the lid 12, the recess 18 formed in the lid 12 is blocked by the index card, defeating the function of the recess 18. To overcome this drawback, the present inventor has disclosed an index card 51, as shown in FIG. 3, which avoids closing the recess 18.
The index card 51 of FIG. 3 has a folded portion 52 for fitting in the pocket portion 14 similar to that of the earlier index card, but a flat portion 53 is smaller in width than the above-mentioned flat portion 43. More specifically, there is established the relationship L.sub.b &lt;L.sub.a -L.sub.c, where L.sub.a represents the width of the flat portion 43, L.sub.b the width of the flat portion 53, and L.sub.c the depth (width) of the recess 18. With this arrangement, the recess 18 formed in the open side of the lid 12 is not closed by the index card, so that the thick portion 21 of the cassette can be received in this recess.
However, with this configuration of the index card 51, the lid 12 is exposed at opposite sides of the recess 18, and a step is formed between such exposed portion and the portion where the index card 51 is present. This produces instabilities such as rattling. Moreover, powder tends to be produced as a result of the frictional contact between the cassette 20 and the lid 12. This is not desirable from the viewpoints of quality control and appearance.